We often need more USB ports, especially for laptops. There are plenty of small hubs that add more ports. They’re cheap enough and we have a couple.

There are two main types of hubs: powered and unpowered. The powered ones come with an adapter that plugs into an electrical outlet. Some devices that use USB connections, like external hard drives or scanners and printers, need more power than they can pull from the computer itself, and for these kinds of accessories it’s best to get a hub that has its own power supply. These are widely available and sell for around $15-$30.

We recently came across one with a difference: the “Ultra Buddy,” which we found for $40 at TigerDirect.com. The difference is that it can be connected to two computers at once.

In short, the Ultra Buddy acts as what used to be called an A/B switch. This can partially substitute for a network. Two PCs can be connected to the back of the hub and up to seven USB devices plugged into the front. LED lights on top indicate which are in use. These can’t be used by both computers at the same time. To switch between computers, you just press a button. LED lights on top of the hub tell the user which ports are in use.

If you don’t want or need to connect two computers to the same hub, you might like the DUB-H7, a 7-port hub from D-Link that sells for around $20 after a $10 rebate at Amazon.com. An unusual feature of this hub is that is has an “upstream port” to connect to still more hubs. You can keep chaining hubs in line to connect up to 127 additional devices. We never came across anyone who needed that many.

The power adapters for both these hubs are the slim-line type, which means they don’t block the other sockets in a power bar when you plug them in. The fat transformers that come with most equipment are very annoying since they inevitably take up two spaces on a power bar or block the neighboring socket when plugged into a two-socket wall outlet.